Attachments
by Arendellecitizen
Summary: After losing her arm in a tragic accident, Elsa is offered a chance to partake in an experimental process that will give her a new cybernetic arm. One that can feel the same as an organic limb. But what she doesn't realise is that this procedure will come at a cost: her sanity. (Elsanna, Slight Kristanna, Incest, Modern Au)


"So Rapunzel and Eugene are dating now, which means I've got to buy like three presents for them at Christmas," Anna told Elsa over her car phone.

"I'm sure you'll find something on Ebay for them," Elsa replied. "That's what you usually do in this situation."

Anna and Elsa had been living together for a while now. Anna had recently moved up from their home town of Arendelle and had been living with her sister up in their mountain retreat. Elsa enjoyed her sister's company, especially when her job meant she had a lot of work to do. Anna could be there to keep her company, as well as motivate her.

The mountain road in front of her was dark and gloomy. Elsa could barely see a thing out of the front windscreen of her car.

"Maybe so. Want me to put the meatloaf on now?" Anna asked her sister. "Those roads can be a very long and tedious drive."

"Sure, keep it warm for me," Elsa answered, "by any means necessary."

"Will do, sis," Anna responded.

Elsa smiled and looked at the picture of her and Anna that was on the windscreen, reminding herself of the happy times they'd had as children.

At that moment, a large bang was heard from the outside of the car.

Elsa clutched the steering wheel, trying to keep her car under control. She realised that her car's rear tire had just burst and had sent her car careening out of control.

Elsa tried to pull the wheel to the left, but it was too late.

Her car smashed through the barrier on the side of the road, sending both her and the car tumbling off the cliff.

Elsa felt her body being tossed around like a rag-doll in the car, eventually coming to a stop when the car hit the bottom. She looked down and saw a piece of the dashboard had crushed her arm and that she was losing blood.

Elsa tried to reach the car phone, but then everything went dark.

xXx

When Elsa awoke, she was in a hospital bed, bandaged up. She heard the sounds of a life support machine beeping around her.

"She's awake!" a nearby voice called out.

Elsa looked to the side to see Anna walking towards her.

"A-Anna?" Elsa said weakly. "Where am I?"

"A hospital," Anna told Elsa, sitting by her. "You're gonna be okay."

"I can't feel my arm," Elsa said.

"There's a good reason for that," Anna replied, her voice filled with regret.

Elsa looked at her arm and saw that it wasn't there; it was just a bandaged stump.

"Your arm was so mangled and mutilated in the crash that they had to just cut it off," Anna explained. "I'm sorry."

Elsa began to cry. "Oh God."

"It's fine, Elsa," Anna comforted her. "You'll make it through this."

Elsa reached out with her only arm and hugged her sister, crying in her arms.

Anna hugged Elsa back and patted her. "Shhh. It's okay. It's gonna be okay."

xXx

"Are you sure you want this, Miss Frost?" The doctor asked Elsa. "This procedure is very experimental."

"I wouldn't be asking you if I didn't want this, doctor," Elsa sternly replied. "Can this cybernetic arm really replace my human one?"

"In theory, yes," the doctor began. "You see, our prosthetics are fitted with a computer that is linked directly to your brain, so they can act more like organic limbs."

"So it will feel like my arm was never amputated at all," Elsa surmised.

"That is correct. However, the process has never been successful; most of the other test subjects either went mad or killed themselves some time after their operation. Are you willing to take that risk?"

Elsa nodded. "I am."

A few hours later, Elsa was put on the operating table, an oxygen mask over her mouth to keep her asleep.

Outside the operating theatre, Anna stood watching the operation through the window. She saw the doctors begin to cut open and sever Elsa's blood vessels, preparing to replace them with wires, machinery, and fiber-optics linked directly into her brain.

"Hey, Anna," a girl called to her.

Anna smiled, recognising her girlfriend. "Hey, Krista."

Krista was Anna's girlfriend since she had graduated from high school. While they hadn't talked much in person since Anna had started living with Elsa, they had always been able to keep in touch online.

The blonde-haired girl gave Anna a cup of coffee. "How's Elsa?"

"They've just started," Anna replied. "Elsa is going to be in there for four hours now."

"Do you think this cyber arm will work?" Krista asked.

Anna sighed. "I dunno, Kristy. I've seen how Elsa's been ever since she lost her arm. Depressive, tired, angsty. I'll be glad when she's better."

"Your sister's tough, I'll give her that," Krista said. "She'll make it through this."

Anna kissed her girlfriend on the cheek, "I'll tell Elsie you said that, and she'll be very grateful."

Soon the operation was complete, and Elsa was moved to a private room to adjust following the operation.

Anna entered the room, hoping her sister was okay.

Elsa was lying in her bed, reading a book. Her arm had been replaced with a white, robotic replacement. Its wrist was lined with buttons and its fingers looked like claws, tipped with rosy pink nails.

"Elsa?" Anna inquired. "How do you feel?"

Elsa looked at Anna, smiling. "I've never felt better, Anna."

Anna was surprised. Elsa was smiling, for the first time in months. "How does the new arm feel?"

Elsa held out her robotic appendage and showed it to Anna. "Like a real, organic limb. It's amazing." She touched Anna's cheek with the arm, stroking it gently. "I can actually feel you, your soft, sweet skin."

Anna pressed her hands on Elsa's robot hand and smiled, "I'm happy for you, Elsa."

xXx

Over the next few weeks, Elsa and Anna's lives changed for the better. Since getting her robotic arm, Elsa had a new lease of life. She was able to get a promotion at her job, spent more time with Anna, and even wrote a book.

Anna was very proud of her sister, but she felt like something had changed in her. Anna didn't care at the time, though; she was just glad her sister was happy again.

It all changed one night, however, when Anna went out to dinner. She was dining with Krista, the night being their four-year anniversary.

"You look good tonight," Krista told Anna. "I like your dress."

"Thank you," Anna replied, smiling at the compliment on her green dress. "Elsa bought it for me; she said it brought out the colour of my eyes."

Krista smirked. "I can think of something else that'll bring out the colour of your eyes." She got out of her seat, getting down on one knee next to Anna. She took out a ring from her pocket and held it up to Anna. "What do you say, feisty pants?"

Anna covered her mouth and jumped into Krista's arms. "Yes! Yes! A million times yes!"

The entire restaurant they were in began to cheer for them.

Anna hugged her girl friend tightly, "Oh my god, Krista, I never knew you would propose to me."

"I've been meaning to do it for a long time," Krista explained, "but I never found the courage. But after spending the past four years with you, I know that you're the one for me."

Anna blushed softly and kissed her. "Thank you."

"Can you move in with me after we're married?" Krista asked. "I know you've been spending a lot of time with Elsa recently, so if you want me to move in, I won't mind."

"I'll ask Elsa about it," Anna told her. "Besides, she likes you, so I'm sure she won't mind."

After parting ways with her new fiancee, Anna drove back home.

"Elsa! I'm back!" Anna called out. "I have a surprise for you!"

"I'm in the kitchen!" Elsa called back, sounding more cheerful than ever.

Anna entered the kitchen to see her sister was making brownies, using her cybernetic arm to whisk the mixture rapidly.

"Oooh, brownies, my favourite," Anna commented.

Elsa smiled and took the spoon out of the mixing bowl. "You can lick it when it's done."

Anna grinned. "So, you wanna know the big news?"

"Go on," Elsa said encouragingly.

Anna held up the ring on her finger to Elsa. "Krista and I are getting married!"

Elsa's expression suddenly turned from cheerful to saddened. "W-what?"

"She and I are getting married, and I was wondering if it was okay for me to move in with her, or her to move in with us," Anna explained.

"No," Elsa simply said.

"W-what do you mean no?" Anna stuttered.

"No, I won't let you marry her," Elsa sternly told her. "She's too good for you."

"Elsa, what are you talking about? This is Krista, not some random girl I just met," Anna replied.

"I don't care," Elsa argued. "I need you with me! You're all I have!"

Anna felt shocked. Elsa had never been like this before. Her sister didn't seem herself; it was like some outside force was controlling her.

"Elsa, what's gotten into you?" Anna questioned. "You've never been like this!"

"I've seen things, Anna," Elsa argued. "I've seen how love can destroy one's heart and tear it in half. I am better than anyone now. I am superior!"

"You're crazy!" Anna said, "in fact you've been acting weird ever since…"

At that moment, Anna finally realised why Elsa had been acting weird lately. It was her robot arm.

"Elsa, it's that weird arm of yours," Anna tried to tell her. "It's done something to your head."

"No. We are strong," Elsa snarled, her voice taking on a more sinister and malevolent tone. She reached out with her robot arm and grabbed Anna by the neck, pushing her against the wall, "I thought you cared about me!"

"I do, Elsa!" Anna croaked, feeling her throat being crushed by Elsa's robotic strength.

"Then why do you want to abandon me for someone else? Am I no good for you?!" Elsa snarled.

Anna knew she had to act fast. "I'm sorry, Elsa." She kicked her sister in the gut, forcing Elsa to lose her grip on her.

Elsa groaned in pain, giving Anna the chance to run upstairs. She ducked under her bed and pulled out her phone, typing the police number into it. But as luck would have it, the phone had no signal.

"Fuck!" Anna swore under her breath.

At that moment, Anna heard the sound of footsteps marching up the stairs. "Oh, Anna?" Elsa's voice cooed. "Where are you, baby sister?"

Anna stayed under the bed, not wanting to go near her clearly insane sister.

"I just wanna hug you...and TEAR YOUR HEART OUT!" Elsa growled.

Anna gulped. Elsa was going to kill her if she didn't do anything.

As Elsa walked by the bed, Anna grabbed her by the foot, causing Elsa to fall flat on her face. Anna quickly got the wire from her hair dryer and tied it around Elsa. "I'm really sorry about this, Elsa."

"You fool!" Elsa growled, enraged. "You'd do this to me, your own flesh and blood? What kind of a monster are you?"

"The kind that saves you," Anna replied.

She reached over to where Elsa's arm was, finding a button on Elsa's shoulder.

"No! I'll be broken if you press that!" Elsa pleaded.

"Better broken than insane, Elsa," Anna remarked.

Anna pressed the button, causing Elsa's robot arm to detach from its socket. Elsa suddenly went limp and weak, her eyes closing. Anna grabbed the robot arm, which was still active and trying to struggle against her. In her best Arnold Schwarzenegger impression, Anna quipped, " _Hasta la vista_ , baby." With that, she tossed the arm out of the bedroom window and into the canyon below.

"A-anna?" Elsa's weak voice called to her.

"Elsa!" Anna exclaimed, rushing to her sister's side.

"Are you okay?" Elsa asked.

"I'm fine," Anna answered, untying Elsa. "What about you?"

"Dizzy," Elsa explained.

"Do you remember what happened?" Anna inquired.

"Yes, I remember," Elsa said. "Oh God; I tried to kill you!"

"It's okay. That was the robot part of you talking, not the real you," Anna comforted Elsa.

"I should have listened to that doctor's advice," Elsa stated. "He told me that things like this happen with those limbs."

"Then we'll just have to find you a new arm that won't try and kill me," Anna answered.

xXx

A few days later, Anna watched from the outside of another operating theatre. This time, however, Elsa was having a biologically cloned arm rather than a cybernetic one, which was guaranteed to not drive her insane.

Krista walked over to Anna, placing a hand on her shoulder. "I'm sorry this happened, Anna."

Anna looked at her and sighed. "No, it's my fault. I should never have accepted your proposal."

"It's fine," Krista responded. "These things take time. We'll work it out."

Anna shook her head. "No, sweetie. I should never have agreed to marry you. I realise now there's someone else who truly does love me." She slid the ring off her finger and gave it back to Krista.

Krista refused, handing it back to Anna. "No, you keep it. Give the ring to whoever you think deserves it."

Anna smiled. "Thanks, big girl."

Two hours later, Elsa's surgery was finished and Anna was invited to go see her.

"Anna!" Elsa cheered, seeing her sister again.

"Hey, Elsie," Anna replied. "Is the new arm okay?"

Elsa held up her new flesh and blood arm. "Feels amazing, and not murderous."

"Good," Anna replied, sitting by Elsa. "You know, this whole experience has taught me two things."

"And what are they, Anna?" Elsa wondered.

"How much I mean to you," Anna answered, "and how much you mean to me."

Elsa blushed. "Anna."

"Elsa, do you love me?" Anna asked.

Elsa looked at her sister and smiled. "I guess I do. I've loved you ever since we were kids."

"Then do one thing for me," Anna replied. She got down on one knee by Elsa's bed, holding Krista's ring to her. "Marry me."

Elsa smiled. "Deal."

Anna slid the ring on her sister's finger, kissing her gently.

 **Author's note:** Based on an idea by my friend, Nona.


End file.
